Minutes of the Dragon meeting May 21st
Submitted by Jennifer Fallis
Attendance: Jenn F, Rachel L, Dave O, Dave H, Lothar B, Mohan C, 
Mike  L, Peter P, Alan C, Sabine E, Cybele J

Minutes from last meeting:
-may have been some omissions in the run plan for the past week but that
hardly matters now
- item 4 replace "16N(p,g)" by "21Na(p,g)"
-Otherwise minutes accepted
Business arising:
-The compiled beam time as asked for in the minutes from the previous
meeting were as follows:
        May 10th 14hours
        May 11th 14hours
        May 12th  7hours
        Total 4500epA h -> 1x10E13 of 21Na

Review of Past Weeks beam time:
-nothing seen at 360 (330 Center of mass) 
-480 (E beam) 3X10E13 particles, no recoil-gamma coincidences seen
-resonance seen at 565 at low end of the energy target.  at 580 we were
seeing 3 times the yield at 212
-Friday it was discovered that Q10 was being supplied with 2 times the
correct current.  It is uncertain when this started or how without us
noticing a reboot.  May not have affected the energy at 360 but would have
when at 480.
-There is a Water leak near the T1 target (10L/h Fri., up to 18L/h now) 
As a result beamline 1a is losing beam after sometime around 8:30 tonight.
Control room can change energy with a stable beam,
***no reason to believe tonight's night shift will be cancelled***

Plans:
-Joel would like to get the electronic dead-time down and run with a lower
threshold at 360 where we didn't really see anything, may possibly have
been that we missed events because of a multi-step gamma cascade.

The detector measures gamma-rays with energy greater than 2Mev alright but
has troubles below.  The deadtime caused by the ADC busy gate is currently
35 microsec with additional deadtime caused by reading the memories, which
is measured using the ratio of the Acquired/Presented scalers.

The proposal would lower the ADC time to 4.5 microsec if there is low H
rate from the strip detector. Events with good H would still have a
35microsec deadtime.

Challanges are to find the gates.
There were questions about whether this is risky before the last run, but
it can't be tested without the radioactive beam and 360 can't be run well
without it.

-There was also a proposal to measure the energy by TOF. This would
require measuring the TOF of protons through the seperator and is more
conveniently done with stable beam. It would take a few hours and would
have to be at an energy around 360. One reason for this would be to check
for reasons the values found for resonance energy may be less than in
literature.

-There was a discussion about the priorities of different measurements,  
returning to 360 vs. choosing a new energy at a higher resonance (600?)

360:
-We potentially can't get a good reading without the change in electronics
-stering may be off due to Q10.
-we've only looked for it at one energy
-We may have missed points due to the electronics
-Our current data would imply that current brancing ratio as given in
litterature is off and that one breaks down into 4 instead of 3.

At other energies:
-we could publish and 'sell' what we have and proposals to ECC beyond
scope of this meeting
-maybe some troubles with reproducibility for 822 but better for 212.  
-direct capture probably not very strong.  This has been estimated but no
thorough calculations have been done.

Decisions and Tasks:
-We will run at 355 keV and Joel will start on the electronics.
-We will also try measuring the TOF of the protons on the
stable beam today.
-Shawn will look at data from energies under 800
-Alan and Sabine will look at the 822 data
-there was mention of someone looking at what the leaky beam is doing to
try and answer the Q10 problem but no name was given.